1. Why do TWI programs strictly separate
the two languages for instruction? Is there research to support this
practice?

It is
important that two-way immersion teachers help their students access each
language of instruction through that language. Exposing them to consistent
periods of instruction through each language is one way to help them figure out
how the language works. Systematic translation of information is ineffective and
can undermine students’ second language development for several reasons:

If students know
that a translation in their stronger language will be provided, they are
likely to tune out instruction in their weaker language.

Teachers who rely
on translation are less likely to make appropriate accommodations for comprehensible input through the
second language—that is, they are less likely to try to adapt the language
of instruction to the learners’ level of comprehension.

Translation is
likely to be biased towards English during instructional time in Spanish or
other
partner languages. Too much
reliance on translation can significantly reduce the time spent working in
and through the partner language.

For
these reasons, the importance of language separation is supported by dual
language researchers in
Dual
Language Instruction: A Handbook for Enriched Education
by
Cloud, Genesee, and Hamayan (2000) as
well as
Dual
Language Essentials for Teachers and Administrators
by
Freeman, Freeman, and Mercuri (2005).

However, this is not to say that the two program languages should never be used
simultaneously during instruction. Classroom discussions
about
language, such as cross-linguistic comparisons of vocabulary (e.g., cognates)
are appropriate contexts for using both program languages together, as this type
of joint use can strengthen students’ development in each language as well as
foster important links between the two languages (August,
Calderón, & Carlo, 2002;
Carlo, August, McLaughlin, Snow, Dressler, Lippman, Lively, & White, 2004). Similarly,
because of the inevitable language shifts that occur when two different language
communities come together, many Spanish speaking communities in the United States
speak a blended variety of Spanish and English, and it can be appropriate to
provide opportunities for students in these communities to use such hybrid
language forms on occasion (Hadi-Tabassum,
2002).
Such conscious teaching strategies support bilingual development by building on
all the linguistic resources that students have and helping students to
recognize sociocultural cues about when it is appropriate to use standard or
non-standard forms of a language. However, TWI teachers must be very
judicious in their simultaneous use of both program languages, and be conscious
of how, why, and when they adopt this practice. The simultaneous use of both
languages for translation of academic content is clearly not recommended.

In the
50/50 dual language programs of School District 54 in Schaumburg, IL,
teachers have found that when language separation is maintained in time, place,
teacher, and content, students’ language production in the
partner language increases over time. They
have observed this in Grades 2, 3, 5, and 6 in both their English-Spanish and
English-Japanese programs.

Because
research has shown that a
natural language environment encourages the development of communication skills (Dulay,
Burt & Krashen, 1982), the
Key Elementary immersion program in Arlington, VA, Public Schools promotes
the development of a natural language environment and uses this as a guiding
principle for their classrooms. As a result, the program discourages the use of
translation because it disrupts the natural flow of speech. Teachers believe
that if they have high expectations for their students and utilize appropriate
instructional strategies, the students will make great progress in the two
languages of the program.

Finally, while translation of academic content is not considered an appropriate
teaching strategy in TWI settings, it can be appropriate to teach students
translation and interpretation skills at the secondary level, when their
language and literacy skills in both languages have reached high levels. For
example, the
International Studies Program
in the Cambridge, MA Public School District
provides courses in medical and legal interpretation. These kinds of courses
prepare students for jobs that capitalize on the students’ bilingualism and
biliteracy, and are therefore quite appropriate at the secondary level.